When the first multi-lens microscopes were invented in 1590, scientists marveled at their new ability to see small objects and features in the natural world that were previously invisible to the eye and therefore seemingly nonexistent.
What is GD&T? GD&T, namely “Geometric Dimensioning & Tolerancing,” is a symbolic language with which to 1) research, 2) refine and 3) ultimately “encode” the functions of each feature of a machine part by specifying permissible limits of imperfection.